Thionyl bromide

Thionyl bromide

Structure of the thionyl bromide molecule 3D model of a thionyl bromide molecule
Names
IUPAC name Thionyl bromide
Other names Sulfur oxy dibromide
Identifiers
CAS Number	507-16-4 Y
3D model (JSmol)	Interactive image
ChemSpider	61483 Y
ECHA InfoCard	100.007.332
PubChem CID	68176
UNII	N6CU78B13T Y
CompTox Dashboard (EPA)	DTXSID0060143
InChI InChI=1S/Br2OS/c1-4(2)3 Y Key: HFRXJVQOXRXOPP-UHFFFAOYSA-N Y InChI=1/Br2OS/c1-4(2)3 Key: HFRXJVQOXRXOPP-UHFFFAOYAY
SMILES BrS(Br)=O
Properties
Chemical formula	SOBr2
Molar mass	207.87 g/mol
Appearance	colorless liquid
Density	2.688 g/mL, liquid
Melting point	−52 °C (−62 °F; 221 K)
Boiling point	68 °C (154 °F; 341 K) at 40 mmHg
Solubility in water	decomposes
Solubility	reacts in HBr, acetone, and alcohol soluble in benzene, toluene, ether
Structure
Molecular shape	trigonal pyramidal
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Readily decomposes in air to toxic gases
Flash point	Non-flammable
Safety data sheet (SDS)	"External MSDS"
Related compounds
Related compounds	SOCl2, SeOCl2; PBr3, Br2
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Thionyl bromide is the chemical compound SOBr₂. It is less stable and less widely used than its chloride analogue, thionyl chloride. It is prepared by the action of hydrogen bromide on thionyl chloride, a characteristic reaction where a stronger acid is converted to a weaker acid:

SOCl₂ + 2 HBr → SOBr₂ + 2 HCl

Thionyl bromide will convert alcohols to alkyl bromides and can be used for brominations of certain α,β-unsaturated carbonyl compounds.

Safety

SOBr₂ hydrolyzes readily in air to release dangerous fumes of sulfur dioxide and hydrogen bromide.

SOBr₂ + H₂O → SO₂ + 2 HBr

References

Mundy, B. P. (2004). "Thionyl Bromide". In Paquette, E. (ed.). Encyclopedia of Reagents for Organic Synthesis. New York: J. Wiley & Sons. doi:10.1002/047084289X.rt098.